Fresh water is a vital resource for human life, and is becoming increasingly precious in remote areas. The logistical challenges in supplying necessary water to remote areas notwithstanding, it is increasingly clear that the humanitarian mission of enhancing the livelihood of local populations is critically connected to the success of the fresh water supply. Due to the ever-increasing need for water, and increased awareness in worldwide water shortage problem, there have been continuous development and improvement efforts in water purification and desalination technology. The majority of the desalination industry is built around infrastructure-scale reverse osmosis (RO) technology due to its energy efficiency, with cities and governments as the main customers. However, these technologies require high pressure generation (to overcome the osmotic pressure of seawater or brackish water) and as such, inherently cater to the large, plant scale reverse osmosis operation.
Since the basic human water need is only 2.5 L per person per day, technology applications for remote locations do not necessarily require extremely large-volume purification of drinking water. Instead, portability and self-sustained (battery or solar-powered) operation, which does not require energy and/or water delivery infrastructures, is more important and critically needed. As a result, small scale, portable seawater desalination and water purification systems that can be operated independently in remote locations will be very useful in addressing the critical needs for clean water, including disaster-stricken areas or other remote, resource-limited settings.
In addition to water shortage just discussed, heavy metal contamination in ground water is a well-documented problem in certain parts of the developing world10. Long-term chronic exposure to the contaminants in drinking water, even at low concentrations, presents significant health risks to humans, because they form complexes with proteins and peptides via reacting with carboxyl (—COOH), amine (—NH2), or thiol (—SH) groups11. When these metals bind to these groups, the modified biomolecules change structure and lose their function, or form cytotoxic free radicals. Arsenic, cadmium and lead are the most common heavy metal contaminants found in groundwater. Specifically, arsenic exposure through groundwater has been a major health problem in several countries around the world, including the US, Mexico, India, Mongolia, Argentina, Chile and Bangladesh12. In particular, arsenic contamination affects approximately 30% of engineered groundwater supplies in Bangladesh13, and an estimated 35-77 million people in Bangladesh have been exposed to toxic levels of arsenic (>0.05 mg/L)12. Chronic arsenic exposure over this level can cause lung, bladder and kidney cancer as well as skin-related cancer and diseases such as hyperkeratosis, lesions and pigmentation changes.10, 11 Cadmium compounds are commonly used in industry for electroplating, smelting, alloy manufacture, color pigments, plastic and batteries10,14. Adverse health effects to cadmium include kidney damage, skeletal damage, hypertension and cancer.10,11,14 Lead compounds are also often found in waste streams from industries such as mining, smelting, welding and battery plants10. Lead poisoning in infants and children delay physical or mental development and affect their attention span, learning abilities and behavior. In adults, prolonged exposure to lead can lead to kidney problems, high blood pressure, memory deterioration, extended reaction time and reduced ability to comprehend.10,15 
Given the highly toxic nature of these heavy metal elements, and the economic factors relevant to the regions suffering from groundwater contamination, developing an efficient, low-cost heavy metal removal process would be desirable. Current methods for heavy metal removal rely on coagulation-precipitation of metal contaminants, induced by adding chemical coagulants, followed by filtration of solids. While this technique is widely used and could potentially be implemented relatively inexpensively16-18, multiple coagulant chemicals should be used for different metal contaminants.
Membrane processes (such as reverse osmosis) are widely used for seawater desalination, but require expensive water purification and delivery infrastructures. In addition, the membrane is prone to fouling, and heavy metal rejection rates could decrease over time19. Electrochemical methods, such as electrocoagulation and electrodialysis are also used20, with several advantages such as less stringent requirement for waste management. However, these electrochemical methods generally involve higher power consumption than other methods, especially when the source water salinity is high (brackish or sea water). Recent results of separating E. coli and red blood cells from a source water clearly demonstrated that ICP can also affect (potentially pathogenic) cells and biomolecules21. Therefore, the technology has a potential for a portable, small-scale (sufficient for a person or family), self-powered (either by battery or solar cells) seawater desalination and disinfection system, which is not currently existent.